My old 03 used to run pretty low oil pressure (lower w/Syn). Now with the 05 ...I'm thinking about delvac syn. Any 05's having low oil pressure at idle? I would like to run Delvac syn about 8000 miles/change vs about 4,000 on my rotella.

LLY normally runs low after warm-up. Around 30psi. Good idea to switch to synthetic if you want to increase your change intervals. Much good info if you do a search on the topic. Good luck.

Low at low idle high at high idle, with my Delvac 1.

I just had my oil sending unit replaced this week as it went to zero a few times when the truck was hot. Scared the **** out of me. It did the same thing to the service manager. It was working very eradicly and now new one is very very smooth. Problem start right after oil change at high temps pulling 5er. Everything seem good now. Temperature gauge never moved. Definitely the sender unit.

My low oil pressure problem has returned, even after new sending unit. Seems related to going around corners and also when braking, even without any trailer in tow. I'm going to change oil and filter again as this is when problem started. The Dinging is driving me crazy.

Please help. Send PM if possible.

Ahh yeah, my truck used to run crazy high oil pressure with Rotella dino oil (like the gauge would be pegged at ~115 PSI on startup. Now that ive switched to Rotella Synthetic, it runs around ~30 or so at idle and around 60-70 on the highway. I wouldnt worry about it.

---Ben

Mine still has the factory oil in it, but it runs about 25 at idle and 45 to 50 at highway speed, at full operating temp.

I switched from Delo 400 to Mobil 1 truck and suv 5w40 a couple of thousand miles ago. The oil pressure is about the same at idle but at highway speeds it runs nearly 60 now or just slightly higher.

The motor SEEMS to run better on this synthetic oil (could be just the difference between dirty Delo 400 and fresh Mobil 1) and I believe I get slightly better fuel mileage. I plan to change every 10,000 miles. If I drive at 50 to 55 mph and the road is mostly level I can get 23+ mpg. At 65mph I get nearly 21 and that is hand calculated. My tows in the mountains are too short to get a handle on the mileage.

I got a mileage jump at about 8000 miles of about 2mpg.

05 LLY D/A CCSB 4WD, everything stock and just over 10,000 miles on it.

Dan Druff,
Don't wear black around me.:)

Ive seen more engines ruined with synthetic crap than any other kind of oil, in almost every kind of diesel engine in any kind of environment. You guys need to stick to normal service intervals, even up to 10000miles between with mobile delevac, or Delo400. Ive never lost any of my engines with patrolium based oils, but have overhauled several for those who thought they were doing great with buying sinthetic, im talking diesel engines in tractors which normally last between 14-18000 hrs, only lasting about 4-6000 hrs. No lie fellas. Stick to the real stuff.

Interesting......................Why?